1. Field of the Invention
A recently developed process for the production of furan involves treating a starting material such as butadiene in the presence of oxygen with an aqueous catalyst system comprising iodine, preferably from an alkali metal iodide, copper having an average oxidation state between 1 and 2, a solubilizing agent for cuprous ion which is soluble in water and forms a water soluble complex with cuprous ion and at least 20 moles per liter of water, the system having a pH value of less than about 2. Such a process is disclosed in U.S. Pat. Nos. 4,172,838; 4,257,960 and 4,268,421. When operating this process a black, amorphous, intractable, insoluble material is produced as a by-product. The present invention relates to an in situ process for disposal of the above-described by-product by oxidation. Removal of the by-product solids by filtration can result in large copper losses and some iodine loss due mainly to occlusion of catalyst solution in the wet filter cake.
2. Prior Art
British No. 1,027,655 discloses a process of oxidizing organic products and especially aldehydes and ketones containing 1-6 carbon atoms at 50.degree.-120.degree. C.